Continuous absorption machine



E. ALTENKIRCH CONTINUOUS ABSORPTION MACHINE June 1.3, 1933.

Filed Dec. 11, 1930 Patented June 13, 1933' UNIS-TED s'raras rATENrOFFICE EDHUND ALTENKIBCH, OF NEUENILAGEN NEAR BERLIN, GERMANY, ASSIGNOR,BY KESNE ASSIGNMENTS, TO THE HOOVER COEPANY, OF NORTH CANTON, OHIO, A.

CORPORATION OI OHIO CONTINUOUS ABSOIlvPiTION MACHINE Application fledDecember 11,1980, Serial No. 501,519, and in. Germany December 7, 1929.

M invention relates to improvements in contlnuous absor tion machines.

" .the absorbing solution substantially.

In continuous a sorption machines with ad- I mixed neutral gas, it isknown to make the vapors of the working medium evaporating in takingheat from the surroundings, reach only through difiusion. The knownabsorption machines of this kind contain so much neutral gas-in thedifiusion chamber that the difference between the evaporation andcondensation pressures is practically completely balanced. 'However,even if they are operated with water cooling and therefore at acomparatively low absorber temperature, their efliciency is poorandproves to be quite insuflicient. But the solution of the problem vbecomes entirely impossible if, at higher temperatures of the absorber,as with air cooling These conditions are radically changed ifcomparatively lowtemperatures of the evaporator are to be obtained.

according to .the invention neutral gas 15 added to the working-mediumvapor in the diffusion chamber in such small quantities that the totallow compared to the pressureof the vapor of the workingmediumalone'atthe normalte'rm perature of'vaporization. With,the subjectmatter of the invention,

chambers in which they working-medium vapor is driven oil and condensed,is therefore substantially maintained, in spite of the admixture ofneutral gas.

W L Byth s means aniextraordlnary. increase in output and e'fiicl'encyisobtained. The

reason for this is that the rate of diffusion which the efliciency'depends, remain constant.

To maintain the said diflerence of pressure when the machine'is inoperation, pumps or valves may be employed. It is, however, moreadvantageous to maintain, according to th'e further improvement,the-saiddifierence -of pressure'not equalized by the neutral gas,

order not toexceed the desired moderate wall 11 of. the vessel andenclosed by a'he through the means of liquid columns. In

20 cm water head) pressure of; the mixture remains;

the difference ofpressure between the difiiusion chamber and the heightfor the machine, particularly for Q the, normal temperature, ofvaporization a comparatively low vaporpressure (less than Substances ofthat kind are, for example, water (absorption means: sulphuric acid oralkali), toluene (absorpf tion means; chinoline or paraflin oil) etc. Inthe drawing aflixed hereto, an embodiment of my invention is illustratedinconnect-ion with an; absorption machine serving to produce cold.

' In a generator solution) is heated .by means of an electric heatingelement 2. The water-vapor bubbles developed thereby lift the solution,which has,

"1, absorption solution (lye v now become weaker in water, in anupwardly extending p1pe 3 into a vapor separatlon chamberd where thewater vapor and the ab} sorption solution separate. Whilst the watervapor is conveyed through apipe 5 to aniair cooled condenser coil 6where it is condensed,

shaped pipe into a ring-shaped collector 8 disposed in the likewisering-shaped gas absorber and the evaporator. Around the bottom of thering-shaped collector 8, at its inner edge, openings 10 are provided forthe absorption liquor.

the absorption solution flows through a U- -75 I chamber 9 of a closedvessel, containing the The vessel containing the gas chamber 9 hassubstantiall the sha e of i an upright cylinder.

inner wall 12, enclosing a chimney-like space 13, remains free. Thehollow space 9 is lled It is dou 1e walle, and so constructed that thesaidring-shaped hollow spaced), between the outer wall 11 and the withthe neutral gas}('nitrogen), into'which I I the evaporating working.medium difiuses. The said hollow space 9, which is hereinafter calledthe'difi'usion chamber, has at the topa widened part '14 and at thebottom a widened part 15.

lector 8 for the absorption solution and also a ring-shaped channel 16serving as a collector for the condensate. At its bottom part, the

I The-widened ,part 14 at the top con- Q tains the above mentionedringshaped colring-shaped channel 16 is fitted in the top of arefrigerating chamber 22' surrounding the iod insulating mass 21. Thecondensate flows to .the collector 16 through a pipe 17 coming from anequalizing vessel 18. The equalizing vessel 18 is connected at thebottom through a U-shaped pipe 19 and at the top through a pipe 20 witha condenser 6 in the manner shown in the drawing.

At its bottom part the pipe 20 is provided with a few coils, in whichthe water vapor which has not been liquefied can be condensed.

The bottom widened part 15 serves to take a store 23 of absorptionsolution flowing from the ring-shaped space 8 through the holes 10 andtrickling down over the wall 12 of the vessel. The wall 12 of the vesselis covered from top to bottom with-a distributing structure '(e. g. aporous substance) 24, whereby the most favourable conditions areobtained for the absorption of the working-medium vapor. Thisworking-medium vapor is formed in the diffusion chamber from thecondensate coming from the ring-shaped collecting channel 16 andtrickling down the wall 11 over a distributing structure 25 covering 2same. During the trickling down the working-medium vapor diffuses intothe neutral gas. Working medium which does not' evaporate passes intothe liquid supply 23. From the latter a U-shaped pipe 26 forming a heatexchanger with the pipe 7 conveys the rich absorption solution back tothe generator 1.

The heat of absorption produced by the absorption of the water vapor outof the gas mixture in the diffusion chamber 9, is carried away by thecurrent of air formed in the chimney-like space 13 surrounded by thewall 12 of the vessel.

The cooling chamber 22 arranged concentrically round the diffusionchamber 9 and kept at a low temperature by the cold produced through theevaporation, is protected by means of the insulating mass 21 from thepenetration of heat from the surroundings.

The action of the above arrangement is as follows:

The water vapor developed from the absorption solution by heat appliedto the gen-' erator, passes, after being separated from the the solutionof reduced water content in the vapor separation chamber 4, to thecondenser -6, where it condenses and assumes a cooling temperature of 40C. at a pressure of a water head of about 7 5 cm. In the diffusionchamber 9, filled with nitrogen a mixture of water vapor and nitrogentakes place when the condensate evaporates, the said mixture assuming atemperature of evaporation of 5 C. and. having a pressure of a waterhead of about 15 cm. The danger of the condensate solidifying may beavoided by adding to it asmall quantity of lye. This can, for example,be done by a suitable arrangement and dimensioning of the vaporseparation chamber 4 and the "3PM" pipe 5.

The heat produced by the absorption on the wall 12 is carried away atabout 45 C. by the current of air passing through the space 13.

The difference of pressure to be maintained by liquid columns amountsaccording to the above to a 7515=60 cm water head. As the evaporatingpressure of the Water alone at -5 C. corresponds to the pressure of a4.3 cm water head, the gas pressure of the mixture of nitrogen and watervapor, which has the value of a 15 cm water head, is but little abovethe vapor pressure of the working medium alone. Itis on the other handconsiderably lower than the condensing pressure of the working mediumamounting to a 75 cm water head. The height of the liquid column fromthe level of the surface of the liquid store 23 to the middle of thegenerator 2 is, as will be seen on the drawing, greater than the heightof the liquid column between the point of union of the condenser 6 andthe pipe 19 on the one hand, and the point where the condensate flowsout of the equalizing vessel 18 on the other hand. The depth ofimmersion required for an undisturbed operation of the generator isthereby assured, so that a comparatively small development of vaporbubbles in the generator 1 suffices to lift the absorption liquor in theupwardly extending pipe 3 up to the vapor separation chamber 4.

Instead of arranging the refrigerating chamber 22 concentrical to thediffusion chamber 9, it may also be arranged eccentrically.

Contrary to the manner shown in the example illustrated by the drawing,the space in contact with the air may also be disposed on the outer sideand the chamber to be kept cool on the inner side. Finally, it is alsopossible to place the condenser 6 inside of the chimney-like space 13and in this manner not only to save room but also at the same timeprovide a particularly good cooling arrangement for the condenser. Theconveyance of the liquid by means of gas bubbles makes it possiblewithout mechanically moving parts and without an additional applicationof heat to operate a diffusion machine, in which highheads can beovercome in the liquid circulating circuit. In this way, it is possibleto let the absorption liquid trickle down freely through a diffusionchamber of considerable height. i

I claim as my invention:

-1. In a continuous absorption refrigerating machine comprising agenerator, 2. condenser or liquefier, a common evaporation andabsorption chamber, said chamber containing a neutral gas through whichthe working medium vapor passes over to the absorption liquorsubstantially only through diffusion, said gas being admixed to theworking medium vapor only in such a small quantity that the totalpressure of the mixture of neutraL gas and working medium vapor remains10w comparedto the vapor pressure of the working medium alonemeasured'at the normal temperature of evaporation, and liquid columnsfor maintaining'the difierence of pressure existing between thediffusion chamber on the one hand and the generator and liquefier on theother hand, said working medium havmg a vapor pressure of less than 2.In a continuous absorption refrigerating machine comprising a generator,a con- 1 denser or liquefier,

a common evaporation and absorption chamber, said chamber containing aneutral gas through which the working medium vapor passes over to theabsorption liquor substantially only through difiusion, said gas beingadmixed to the working medium vapor only in such a small quantity thatthe total pressure of the mixture of neutral gas and working mediumvapor, remains low compared to the vapor pressure of the working mediumalone measured at the normal temperature of evapora-- tion, and liquidcolumns for maintaining the -difference of pressure existing between thediffusionchamber on the one hand and the generator and liquefier on theother hand, said absorption liquor consisting of a mixture of water andalkali lye.

3. In a continuous absorption reffiigerating machine comprising agenerator, a condenser or 'liquefier, a common and absorption chamber,said chamber containing a neutral gas through which the working mediumvapor passes over to the absorption liquor substantially only throughdiffusion, said gas being admixed to the working medium vapor only insuch a small quantity that the total pressure of the mixture of neutralgas and working medium vapor re- 9 mains low compared to the vaporpressure of the working medium alone measuredat the normal temperatureof evaporation, and

liquid columns for maintaining the difference of pressure existingbetween the diffusion chamber on the one hand and the generator andliquefier on the other hand, said absorpand i r In testimony whereof Iafiix my signature.

tion liquor consisting of a mixture of toluene paraffin oil. i

EDMUND ALTENKIRCH.

20 cm water head at the normal temperature of evaporation (0 toevaporation

